Sewer construction



1,638,473 Auf@ 9s 927- v, H. cocHRANE SEWER CONSTRUCTION Filed Jun@ 18,`1925 v2 sheets-sheet 1 EE- EJB r' 3' j "."ill 1' 3 ,//l 1g. E1- Mmm a@l l S? s a www@ l l 1,638,473 Aug' 9 1927' v. H. cocHRANE SEWERCONSTRUCTION Filed June 18, 1925 Y 2 Sheets-Sheet 2 61H01 nuja PatentedAug. 9, 1927.

UNITED sTATEs VICTOR E.' OOCHRANE, OF TULSA., OXLAHOIL SEWERCONSTRUCTION.

Application mea .rune is, ma. smal m. sam-s.

This invention relates to improvements in sewer constructions.

The primary object of this invention is the provision of a sewerconstruction, whereby the stresses upon the sewer may be accuratelydetermined.

A further object of this invention is the provision of an improved sewerconstruction embodying novel means of forming the arch upon theabutment, with hinge joints, so as to do away with uncertain stresses inmonolithic construction. A

A further object of this invention is the provision of a sewerconstruction which will materially reduce the quantity of concreterequired with certain types of sewer constructions, such as themonolithic construction, and provide in addition a sewer in which thestresses can be foreseen and safely taken care of.

A further object of the invention is the provision of a sewerconstruction including abutments and -an invert independently connectedby means of flexible joints, so that the invert is prevented fromcarrying any part of the load from the arch or abutments, and furtherproviding an arch section attached to abutments by means of joints whichare so constructed as to fix the location of the resultant thrust at thecenter of the arch section at the joint, so that the arch is vir` tuallytwo-hinged for dead load and fixed or partially fixed for live load.

A further object of this invention is to provide a sewer constructionwhich includes the formation of the abutments, upon which the archbarrel is subsequently supported by means of novel joint constructionswhich permit hinge action of the arch upon the abutments, thus enablingthe arch barrel to adjust itself to the pressure exerted by the fillingmaterial thereover, and to the shortening of the axis caused by thecompressive stresses.

Other objects and advantages of this invention will be apparent duringthe course of the following detailed description.

In the accompanying drawings, forming a part of this specification, andwherein similar reference characters designate corresponding partsthroughout the severalv views.

Figure 1 1s a cross sectional view taken through the completelyconstructed sewer, at a typical cross section, and showing thecomparative formation of the same with the another ste presentrequirement of monolithic structure of the same size; the monolithicstructure being shown in this view in dot and dash lines.

Figure 2 is a fragmentary sectional view taken on a horizontal planesubstantially on the line 2 2 of Fi re 1.

Figure 3 is a sectional view taken through an abutment of the sewerconstruction, showing the rst step in the formation of the sewerconstruction.

Figure 4 is a fragmentary sectional view showing the form work at thejoint between the arch at its springing edge and the abutment.

Figure 5 i's a sectional view showing in the construction of the archupon the a utment, by means of which the same has a hinge action thereonduring the filling of earth or other material over the arch to permitthe arch to settle and adjust itself to the pressure of the .dead load.

Fi re 6 is a fragmentary sectional view showing an alternative 'form ofjoint construction.

In the drawings, wherein for the purpose of illustration is shown only apreferred construction of the arch and a preferred design of the same,the letter A may generally designate the finished sewer construction,which may consist of the abutments B; arch C, and invert D.

In present types of sewer constructions, the stresses may bemaccuratelyfigured only in case the foundations are firm and unyielding, whereas ifthere should be any settlement or rotation of the arch abutment at itsfoundation unforeseen stresses may be set up throughout the arch ring.Some sewer constructions to obviate this require the sewer invert,archesf and abutments to be made very thick, in a monolithicconstruction. This is so especially in-the case of sewers resting up'onsoft foundations, in contradistinction to rock foundations. To obviatethis factor by increasing the thicknesses of the parts of the sewer issometimes inconvenient and expensive. To do away with lsuch uncertaintyof stresses, the novel sewer construction and method of forming the sameherewith set forth has been provided, which will enable all stresses'tobe accurately determined, and requires the use of only about the sameamount of material for a soft foundation, as would be necessary for arock foundation of present sewer constructions. lt is extremelyeconomical as compared with `forms of sewer construction now in use. lnFigure 1 has been given the comparative sizes of sewer constructionsaccording to my method and according to a present known method, in whichthe latter is illustrated in dot and dash lines.

Prior to the forming oit the arch portion C, the abutment-s B andrelerably the invert l) are constructed. lie abutments B are formed toprovide the mein body portion 10, which provides an inside wall surface11 adapted to lie contiguous with the intrados 12a o the arch C. it theout-er side of the body of the abutment B, the abutment extension 12 isprovided, oit any approved length, providing a toot for distribution ofload thrust; the heifrht ci this extension 'l2 between the top suriace18 oit the abutment and the bottom surface 1li thereof, preierablydecreasing towards the outer edge of the extension 12. As a novelfeature ezt the abutment B the same is provided with an invert extensionportion 15, providing a toe, so 'to speak, for the abutment B, whichextends at the opposite side or the abutment from the extension 12, andwhich in reality is a part of the invert oi the sewer A. This toe orinvert extension 15 is of course considerebly reduced in height withrespect to the ebutment, and it has a top surface 18 to lie contiguouswith the invert iiotv surface and provide part of the same.

The reinforcing oit the abutment B plays important part in the sewerconstruction, and during the formation or the abutment, the reinforcingrods or bars 20 and 21 are embedded in the cementitious material of theabutment. @The rods 20 and 2f. are crossed at 2d, and preferably held bya ring 25 or analogous element at this point just upwardly of the topsurface 13 of the abutment E, and which cross location 24 really lies inthe joint space 26 when the arch C is connested to the abutment i3, ashas been illustrated in Figure 5 oi the drawings. rThe bars 2O and 21from the cross location 24 extend upwardly in divergent relation, andprovide the end portions 28 and 29 adapted to be embedded in thespringing portions or' the arch C to hingedly connect the arch to theabutments. The reinforcing bars or rods 20 and 21 extend into theabutment B preferably in divergent relation, at portions 30 and 31, andthe portion 3.0 may terminate at 32, or it may be arcuated and bent lorembedding at la portion 3d extending into the invert or toe extension18, for reinforcing the same. Additional reinforcinof rods may also beprovided along the bottom of the abutment throughout the Width thereof,as has been illustrated in the drawings.

inasmuch as the reinforcing bars or rods 20 and 21 are in compression,it may be advisible to insert stirrups, ties or thrust disneed-17stributing lates 39 land 40 in the abtments B and arc C, adjacent thejoint space 26, to prevent cracking of the concrete or cementitiousmaterial.

The invert D is separated from. the inver extensions 15 of the abutmentsB, by means oli joints t5, which may be any approved flexible or sliconstruction joint, such as tar paper, or ot er elastic substance suchas asphalt, resting directly on the foundation or held in. place bystirrups 46, which at their ends are anchored in the invert andabutment, as is illustrated in Figures 1 and 5 of the drawings. l't isto be particularly noted that with such a construction the main invert Ddoes not comprise the entire invert, but the extension 15 may also beconsidered as included in the term invert. lll/'ith this constructionthe joints are placed much closer to thecenter line of the sewer, thanare invert joints which have heretofore been provided in sewerconstructions of proportionate size. With such construction the invert Eis made relatively shallow, since it does not support any of the deadload thrusts, and the abutments may move relative thereto Withoutracturing the invert main section D,

filter the abutments have been placed, the joint space 26 is filledpreferably with some suitable material that can be removed to permitarch settlement, such as forms made up 01E detachable wedge pieces 50and 51. The inner and outer i'orms of the arch C are of course placed,and the reinforcement 53 and 54C adjacent the intrados and entradossides of the arch are placed, and the concrete is poured and allowed toset in the form provided therelor. After the arch concrete has beensufficiently cured, the forms are removed and the earth or othercovering over the arch is placed. l1 wooden :forms have been used in thejoint space 26 they are removed either before or after the dead load hasbeen placed, and at this juncture the entire weight of the arch and suerposed loads will be concentrated upon t e cross locations 24 of thereinforcing rods 2O and 21, at the center of the joint space 26, and ascan be readily understood, thus denitely fixing the location of theresultant thrust at these points. After the arch has had time to adjustitself, and the earth lill and the foundations have fully settled, thejoint space 26 may be pointed up with any suitable filling material 56,which may be cement or some elastic material, such as asphalt. In lieuof using the wooden forms and 5l to support the arch during itsformation, the spaces 26 between the abutments and the arch springingends might belled with some elastic substance, as asphalt, which willremain permanently in place. This construction is preferable in theevent that it is imprac` ticable to place the full amount of earthfilllil@ lil)

ing on the arch at the time of construction, in which case the layer ofelastic material is made as thin as may be, and at the same time topermit of a suicient amount of rotation of the arch relative to theabutment. To prevent access of water to the reinforcing rods 2O and 21,longitudinally extending metal diaphragms 61 and 62'may be used, atopposite sides of the hinge joints provided by the crossing `of saidrods, said diaphragms being embedded in both the abutment and arch ring,and providing, in effect, aclosed channel, as is illustrated in Figure 6vof the drawings.

As to the steps of construction, the preferred method of forming thesewer is to first form the abutments B and the invert D, and the archbarrel C is subsequently supported in the manner above described uponthe hinges formed by the reinforcing rods 2O and 21, orin any otheranalogous manner which will permit a slight rotational movement at theends of the arch. The joint spaces are then filled with cement, concreteor other suitable material, such as elasticv asphalt, although not untilthe sewer trench has been back filled and the filling material allowedto settle, andthe arch to adjust itself to consequent pressures. If suchadjustment cannot be accomplished at the time of construction, the jointfilling material to be of an elastic nature and left in place, beingformed on the abutments B. before the arch C is built. It is alsocontemplated to provide other hinge connections not shown specificallyby the reinforcing bars 2() and 21.

The advantages of the above method consist essentially in the fixing ofthe position of the line of thrust at the center of the arch section andconcentrating it at joints adjacent to the arch support upon theabutments, so as to permit some relative movement between the archbarrel and abutments, without fracturing the sewer construction, as doesactually occur in monolithic sewer construction. It is a fact that withthis im- .proved method of sewer construction, the

arch and abutments can be made lighter in section and with smallerquantities of reinforcing steel than other sewer constructions of thesame size, thus effecting a considerable economy without any decrease instrength.

Thus, briefly, it can be seen that the sewer construction consists of apair of abutments at each side, an invert 'section separated by jointsfrom the abutments permitting relative movement so that the abutmentsmay settle independently of each other and the invert, and preventingthe invert from carrying part of the load of the arch and abutments; andlastly an arch section attached to the abutments by means of hingejoints which fix the location of the resultant thrust at a place whichcan receive the same with- 'fixed for live loads.

out fracturin any part of the sewer construction. T e arch is thusvirtually two hinged for dead load and fixed or partially An additionaladvantage 4is that the improved sewer construction reduces the stressescaused by the arch shortening, so called, as compared with the ordinarymonolithic construction.

Various changes in the steps to place the various parts of the sewerconstruction, shape, size, and arrangement of parts may be made to theinvention herein shown, illustrated and described, without departingfrom the spirit of the invention or the scope of the claims.

I claim:

1. In a sewer construction the combination of abutments having integralinvert extensions, a main invert section, means flexibly connecting themain invert section at its ends with said invert extensions of saidabutments, and an arch superposed upon said abutments.

2. In a sewer construction the combination of abutments having integralinvert extensions, a main invert section, means flexibly connecting themain invert section at its ends with said invert extensions of saidabutments, an arch barrel, and yieldable joint means connecting the archbarrel at its springing ends in a leak-proof connection upon saidabutments for limited relative movement with respect to said abutments.

3. In a sewer construction the -combination of abutments, an arch,reinforcing members embedded in said abutments and in said arch tohingedly connect the arch to said abutments, and diaphragm memberslongitudinally extending along said abutments and arch embedded thereinat opposite sides of each of the joint connections provided by saidreinforcing members.

4. In a joint construction a pair of concrete sections, metalreinforcing members each embedded in each of said sections and extendingacross the joint location between said sections, and flexible metaldiaphragm means embedded in each of the sections at each side of thelocation where the said reinforcing members cross the joint between saidsections, to seal the joint location agiinst access of moisture to saidreinforcing ro s.

5. In a exible joint construction the combination of a pair of concretesections, reinforcing rods embedded in each of the sections andextending across the location be tween said sections whereby to hingedlyconnect the sections together to permit relative movement thereof, and ametal diaphragm member at each side of the location where thereinforcing rods cross the joint location of said sections, each metaldiaphragm member being embedded in each offthe sections and crossing thejoint location between said sections to liquid seal the rods at thejoint location against access by moisture.

6. lin dexible joint construction the combination of e pair of concretesec-v tions, reinforcing rods embedded in each oi the sections andextending across the .locetion between seid sections whereby to bingedlyconnect the sections together to permit relative movement thereof` ametal pbregrn member et each side of the location where the reinforcingrods cross the joint location oi said sections, each metal din bregnimember being embedded in each o' tbe sections end crossing the jointlocation between said sections to liquid seal the rods at the jointlocation against access by moisture, said dexible diapbragms at the critlocation being crimped to facilitate the timing tbereo during relativemovement of concrete sections.

L lin n i'dexible joint construction the coinbinetion of e pair ofconcrete sections, reiniorcing rods embedded in each ot the secg tionsand extending across the location between seid sections whereby tobingedly connect the sections together to permit relative movementtbereoii, a metal diaphragm niember et eacli side of the location wherethe reinforcing rods cross tbe joint location ot said sections, eacbinetel diaphragm member being embedded in eecii mi the sections andcrossing the joint location between said sections to liquid Seel 'tberods at the joint location egsinst eccess by moisture, and sealing;inateriei in tbe joint location between said concrete sections outwardlybeyond said diapnregms;

8. In a sewer constriiction the combination of elon ated abutments eachincluding a body portion and a reduced laterally er; tending invertextension of less height than the body ortion, an elongated invertbetween the invert extensions and in top surface iush relationtherewith, exible joint means connecting and sealing tbe joints betweenthe longitudinal edges of the invert and tbe invert extensions of saidabutments, e. inain arch ring, and metal binge connections embedded intbe ends ont the arch ring and the body portions of the abutments toinount tbe springing ends of tbe ercb ring for some relative movementwith respect to the ebutinents.

9. in a sewer construction tbe combination ot' elongated abutments eachincluding .e body portion and a reduced laterally extendinvert extensionot less height than the body portion, an elongated invert between theinvert extensions end in top surface iinsb relation therewith, dexible:ioint means connecting and sealing tbe joints between the longitudinaledges of tbe invert end tbe invert extensions of seid abutments, e maineren ring, metal binge connections embedded in the ends of tbe eren ringend tbe body portions of the obntrnents to mount tbe springing ends olf.the arcb` ring for sonic relative movement with respect to tbeibutinents, and an elastic non-concrete construction in the jointlocation between tbe springing ends ot the arch ring and tbe abutments:tor sealing end nrotecting the binge rods against deterioratinnfinuences.

vieron n. contienne.

